Fix wchar.h not to redefine WCHAR_MAX/WCHAR_MIN

Change-Id: I6c6f2e020b72cce4c8665133ea0a0c5db977e348
diff --git a/ndk/platforms/android-3/include/wchar.h b/ndk/platforms/android-3/include/wchar.h
index 9a6ce1d..ecbf921 100644
--- a/ndk/platforms/android-3/include/wchar.h
+++ b/ndk/platforms/android-3/include/wchar.h
@@ -70,8 +70,11 @@
     WC_TYPE_MAX
 } wctype_t;
 
+#ifndef WCHAR_MAX
 #define  WCHAR_MAX   255
 #define  WCHAR_MIN   0
+#endif
+
 #define  WEOF        (-1)
 
 extern wint_t            btowc(int);
diff --git a/ndk/platforms/android-8/include/wchar.h b/ndk/platforms/android-8/include/wchar.h
index b9c7b0b..efe60bb 100644
--- a/ndk/platforms/android-8/include/wchar.h
+++ b/ndk/platforms/android-8/include/wchar.h
@@ -70,8 +70,11 @@
     WC_TYPE_MAX
 } wctype_t;
 
+#ifndef WCHAR_MAX
 #define  WCHAR_MAX   255
 #define  WCHAR_MIN   0
+#endif
+
 #define  WEOF        (-1)
 
 extern wint_t            btowc(int);
diff --git a/ndk/platforms/android-9/include/wchar.h b/ndk/platforms/android-9/include/wchar.h
index fea648c..437f52b 100644
--- a/ndk/platforms/android-9/include/wchar.h
+++ b/ndk/platforms/android-9/include/wchar.h
@@ -71,8 +71,11 @@
     WC_TYPE_MAX
 } wctype_t;
 
+#ifndef WCHAR_MAX
 #define  WCHAR_MAX   INT_MAX
 #define  WCHAR_MIN   INT_MIN
+#endif
+
 #define  WEOF        ((wint_t)(-1))
 
 extern wint_t            btowc(int);